新型氧化钇粉末及高纯致密氧化钇涂层的大气等离子喷涂制备

目前采用粉末原料通过等离子喷涂制备的最先进高纯氧化钇涂层的孔隙率通常为3%~5%。这种孔隙率的涂层在严重的腐蚀和侵蚀条件下会释放非常细小的颗粒。高纯氧化钇涂层主要应用于半导体领域,如,干法刻蚀腔室的抗冲蚀保护涂层(含氟和氯的等离子体),并且这些应用的需求条件也越来越严苛。当暴露于这种腐蚀性和侵蚀性气氛中时,涂层的致密度越高,它的耐侵蚀性就越强。侵蚀速率和细颗粒释放的降低将减少维护频率,从而提高生产效率。最近有文献报道通过悬浮液等离子喷涂(SPS)技术制备致密度更高的涂层,但这种新兴的工艺对制备技术提出了更高的挑战,如需要应对非常高的热通量和处理悬浮液作为原料来使用,增加了偏差的风险。本文开发了一种新的高纯氧化钇粉末,采用传统的大气等离子喷涂(APS)这种粉末能制备致密度范围与SPS技术相同的涂层。通过对粉末中颗粒致密度分布的调整和其狭窄精细粒度分布的微调得到一种独特的粉末材料来制备高质量的涂层。相比于通常报道的团聚和烧结粉末,采用Saint-Gobain ProPlasma HP等离子喷枪喷涂这种粉末显著降低了涂层的孔隙率,提高了沉积效率。

Dense and High Purity Yttria Coatings by APS with a New Yttria Powder

Lowering the erosion rate and release of fine particles will reduce the maintenance interval and therefore increase productivity. Recent works have been published on the use of suspension plasma spray （SPS） to achieve denser coatings, but this emerging technology introduces tough industrial challenges like the need to cope with very high heat flux and the handling of suspensions as feedstock with an increase in the risk of deviations. The newly developed high purity yttria powder that will be presented makes it possible to reach the same range of coating densities by conventional air plasma spray （APS） as those obtained by SPS. The fine tuning of the particle density distribution in the powder combined with its narrow and fine size distribution makes it a unique feedstock for very high quality coatings. Plasma spraying of this powder with the Saint-Gobain ProPlasma HP gun leads to dramatic porosity reduction with improved deposition efficiencies at feed rates higher than those commonly reported for agglomerated and sintered powders.